California Air Resources Board

SACRAMENTO - A new study finds that low-income populations and racial and ethnic minorities (Latino, African-American and Asian/Pacific Islander/other) were exposed to greater levels of certain air pollutants and, in turn, suffered increases in asthma-related difficulties, from asthma attacks and daily medication use to work absences and emergency room visits.

The new study was led by Dr. Ying-Ying Meng, co-director of the Chronic Disease Program at the UCLA Center for Health Policy Research, and funded by the Air Resources Board.

Previous research has shown that children, the elderly, racial and ethnic minorities and low-income Californians suffer disproportionately from asthma burdens, such as asthma attacks and asthma-like symptoms. This latest study sought to determine whether the asthma burden disparity is due to exposure to higher levels of air pollutants, greater vulnerability, or both. Vulnerability refers to external factors, such as socioeconomic status, residential location and occupational exposure, which influence the risk of adverse health effects related to exposure to air pollution.

The investigators found that certain populations had higher exposures to nitrogen dioxide or particulate matter, though they were not exposed to greater levels of ozone pollution

They also found that lower-income children (living below 200 percent of the federal poverty level), including Latino and American Indian/Alaska Native children, and African-American and Asian/Pacific Islander adults and children, are more vulnerable to the effects of air pollution exposures compared to high income (living at or above 400 percent of the Federal Poverty Level) white children and adults of the same ages.

Among lower-income asthmatic children, the odds of visiting an emergency room more than doubled for every increase in nitrogen dioxide by 10 parts per billion. Similar two-fold increases were observed relating to the odds of African American adults experiencing daily or weekly asthma symptoms and the odds of Asian/Pacific Islander adults missing two or more days of work per week.

Investigators also observed:

•    Asthma or asthma-symptom sufferers who lived within 750 feet of roadways with high traffic density had increases in asthma-related trips to the emergency room. 

•    Positive associations between asthma outcomes and the number of days for which air quality exceeded state or federal standards for ozone and particulate matter.

•    Compared to white children, American Indian/Alaska Native and Asian/Pacific Islander/other children had a greater increase in the odds of experiencing daily or weekly asthma symptoms for the same increase in nitrogen dioxide. Latino children had a greater increase in the odds of using daily asthma medication for the same increase in PM10, and African-American and Asian/Pacific Islander/other children had greater increases in the odds of daily or weekly symptoms than white children for a comparable increase in PM10.

In all, about 3.5 million adults and 900,000 children in California have been diagnosed with asthma. Millions more suffer from asthma-like breathing problems.

The UCLA study matched health impact data from the California Health Interview Survey to existing air pollutant and traffic data. Annual pollutant averages for particulate matter, ozone and nitrogen dioxide were calculated for 54,000 Californians’ home addresses using data from nearby air monitoring stations.

Some practical ways to reduce exposure to particulate matter pollution can be found at http://www.arb.ca.gov/research/indoor/pmfactsheet.pdf

More information on the study can be found at http://www.arb.ca.gov/research/single-project.php?row_id=64812

ARB’s mission is to promote and protect public health, welfare and ecological resources through effective reduction of air pollutants while recognizing and considering effects on the economy. The ARB oversees all air pollution control efforts in California to attain and maintain health-based air quality standards.